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About pmk

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    Advanced Member

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  • Bike
    OSSA MAR & SY250R

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  • Location
    Florida, USA
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  1. Possibly, take a look at the Sudco companies info or Jets R Us. The items you are asking about, I would suspect are still available in tne aftermarket
  2. It’s an AHRMA rule if the machine were to ever compete in one of those events. Luckily it will not be a part of that organization. Heard from someone that is involved with AHRMA trials, they apparently banned OKO and all carbs unless round slide. Kind of a dumb rule. So now you must spend more money, plus time and have a bike that likely runs worse to compete in an organization that is struggling to get entries. Sounds like a great way to promote vintage entries. Next they will insist on an old school spec tire, the same type tire for everyone.
  3. Date codes are 1979, so they comply with available prior to 1980. Parts are 1980 Yamaha, which was available in 1979, keeping the bike legal as a pre 1980 machine with period correct items. Look close at the details required to do this. I had to “C” notch the frame. The entire pedal setup is redeveloped. I have a cable swaging machine to build the rear brake cable. Essentially, there was fabrication time altering the frame, machining time, and fabrication of detail parts including the cable. All this was after getting the much wider wheel into the swingarm while aligning the chainline. Many hours of sorting it out, designing, fabricating, etc., then having hope it would work. We considered many hubs / wheels before even starting. FWIW, both wheels were completely disassembled. Cleaned, polished, hubs painted and modified as needed. Suffice to say, getting the hub in the swingarm was no simple plug and play task. But seems to give a clean look and functions well.
  4. I currently own and ride a 2005 SY250R that Mike imported and sold back then. It has had a few owners before me. In the gearbox, I have been running Shell Rotella T4 15w40, but have on the shelf and been considering switching to Maxima MTL 80wt but have not swapped yet. As for brake and clutch, I run Pentisone DOT4. The clutch slave I altered by removing the snap ring, as it tends to wear on the slave piston body. I also installed the jamb nut to the inside. Many people mention the arms are soft and fail, or have issues with the slave cylinders, on mine I simply ensured there was no binding or limited stroke to the lave cylinder. During a Ryan Young school, Ryan cautioned me about the brake pads. I will ask him again for details when the brakes need replacing, but he indicated something about the pads touching each other and not clamping the disc, even though pad material was left. Need more details to accurately explain. I have tried the oem white progressive spring, the oem yellow spring and both seemed to allow the rear end to squat more than I cared for. I have made adapters and installed an aftermarket spring the works well with minimal preload. Check the engine mount bolts for tightness. The choke on my bike has been a problematic bother. My latest efforts hopefully resolved the issue of the rubbed disc not sealing well. I made some other changes to improve the reliability of the bike, mainly the fabrication of an air filter guard to prevent water from coming down the airbox under the fender and filling the inside of the airbox. I also did away with the oem rear fender that so far for me was impossible to find at a reasonable price. Mike has been great to talk with and is knowledgeable on these machines. My most recent call to him discussed the ignition timing. I did dial back the timing on my SY to midway between the Yamaha spec and Scorpas setup. I found the Scorpa setup gave random flameouts, that felt like I either had to increase idle speed or take a small amount of timing out. The ADV website allows more photos so if you check there, I posted a topic about the SY and some changes I made. For me, the bike is far more capable than I am. Last event, I asked one of the local higher class riders to try it and give an opinion on the setup. His dad owned SY250s years ago. Within minutes, my SY was doing fine on stuff I would likely never attempt. I installed Dunlop tires.
  5. When we built my buddies 72 MAR, many changes were made, including installing Yamaha wheels and brakes that are period correct. I have ridden his MAR and it will stop, plus has the feel and control pretty close to modern bike disc brake feel.
  6. Just noticed your pen / screwdriver holder...Lycoming or Continental?
  7. You will need to drain the coolant. Remove the kickstart lever. Remove the clutch cover. Remove the small bolts and clutch springs securing the clutch pressure plate. Remove the pressure plate. In the center of the clutch is a pusher, remove that. Next there is a steel ball, remove that, then withdraw the clutch pushrod. With the pushrod removed, the arm should lift out. Accomplish the reverse to reassemble. You may need a new gasket on reassembly. The link below is from a TYZ parts manual and visually explains what I just wrote, sort of. https://us.fowlersparts.co.uk/parts/4120715/ty250z-250-trials-4gg3-1994-999-a/clutch The link posted by Feetupfun is the service manual. That shows a similar sketch, but is handy as it is a workshop manual explaining the clutch disassembly.
  8. Have not had my Scorpa engine apart, but typically you remove the clutch pressure plate, slide the pushrod in, then remove the actuator arm assembly.
  9. Please share photos of how you get tne cable setup to work. I had considered similar and studied the TYZ setup, knowing it would plug and play. Downside was tne clearance from the Scorpas exhaust.
  10. The actuator arm, there is a spring inside the slave cylinder that assures no freeplay between the slave piston and the adjuster pin / arm. Installing the jamb nut to the inside allows the adjuster to be into the slave slightly further, but do not overdo this adjustment as you may find the adjuster pin will scrape the snap ring. Worse still is fully extending the slave piston into the snap ring under hydraulic pressure. Realize too, the slave cylinder is secured via one bolt. This allows during assembly to obtain the best alignment of the actuator arm pin into the slave pistons cup. It all sounds complicated, but is not bad if you take your time getting a good bleed and best alignment when setting it up.
  11. Before taking the time, effort, and money to redesign it, I must ask, is the clutch system properly bled. This system is a closed dead end with no bleeder. To get it bled, you must ensure the adjuster on the lever is not depressing the piston where the fill hole is covered / blocked. When I bled mine from having no fluid, I followed Ryan Young's tip and moved the slave / arm adjuster jamb nut to the inside of the actuating arm. Doing this made it less likely to bottom the slave piston against the snap ring causing damage or no clutch release. Ultimately, The adjuster is proud of flush about 1/2 turn of a thread. As for bleeding, it takes patience and time. You must push the actuator arm to compress the slave piston into the bore. Then slowly pump the lever as you slowly release the slave piston. It take a bit, but the system will fill, and you can see air being expelled into the reservoir. Once you begin to get clutch action, continue a bit more bleeds. Once confident in the bleed, make the adjustment on the lever, but ensure the plunger on the lever has a couple mm freeplay before depressing the piston in the master cylinder. I considered converting to cable also, but stuck with hydraulic. Actually the action is pretty good and the clutch is controlled and predictable.
  12. Fire up the engine, most times the rattle is more difficult to hear then. If it really is a bother, add a slight bit of front brake as you ride, Yes, my 2005 rattles a bit. Could be wrong, but thought I saw in a parts book, O rings are used to lessen the noise.
  13. After accomplishing repairs for leaks and soft spots on my friends MAR tank, it was block sanded to remove any sharp edges, not sanded perfectly true. Leak checked again, pressurized with a bicycle hand pump and submerged. As a person that repairs composite aircraft parts, using that knowledge and experience, we had the paint shop apply these coats. Epoxy primer onto the bare fibreglass surface. A fill primer was applied next. This is a two part high build spray on product that sands easily. Once the final sanding and fill prime layers were accomplished, top coat layers of paint then stripes were applied. The paint shop stepped up and then applied clear over the entire tank outer surfaces. The frame side panels were done the same way. As for not painting myself, couple reasons, one, I do not like to and two is I am not a great painter. Sometimes, claiming to have restored or built a bike, you are allowed some poetic license for specialty services such as welding, powdercoating, paint, crank rebuilds and maybe a few more. Kind of falls under the know your limits rule.
  14. pmk

    Ossa Mar paint codes

    FWIW, it is for sale,
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